A&P Final Exam

18. Define and describe resting membrane potential.

(Resting membrane potential - potential difference across the plasma membrane of a resting neuron) - Approximately -70 mV - Membrane is polarized (negative inside) - Generated by different concentrations of Na+, K+, Cl-, & protein anions (A-) - Ionic differences result from differences in plasma membrane permeability to Na+ (slightly permeable) & K+ (25x more permeable); due to leak channels - Na+-K+ pump maintains concentration gradients

32. Thigh: explain the general functions of muscles in the anterior, posterior, and medial compartments; identify which muscles are thigh flexors and which are thigh extenders

- Anterior compartment - most anterior hip & thigh muscles flex femur at hip and extend leg at knee; foreswing walking phase - Posterior compartment - posterior hip & thigh muscles mostly extend thigh & flex leg; backswing walking phase - Medial compartment - all medial muscles adduct thigh -Flexors: Iliopsoas, Tensor fasciae latae, Rectus femoris, Sartorius (tailors muscle) - Extenders: Biceps femoris, Semitendinosus, Semimembranosus, Gluteus maximus (hamstring muscles)

37. Leg: explain the general functions of the anterior, lateral, and posterior compartments; list which muscles are located in each compartment

- Anterior- dorsiflexes foot & extends toes - Lateral- plantar flexes and everts foot - Posterior- primarily plantar flexes foot and flexes toes (curl toes) Muscles: Gastrocnemius, Soleus, Popliteus

33. List 3 hamstring muscles.

- Biceps femoris - Semitendinosus - Semimembranosus

19. Define the terms graded potential, action potential, depolarization, and hyperpolarization.

- Graded potentials - incoming signals operating over short distances; occur on dendritic and neuron cell body membranes - Action potentials - outgoing signals operating over long distances; occur on axon membranes - Depolarization - decrease in membrane potential; inside of the membrane becomes less negative than resting membrane potential - Hyperpolarization - increase in membrane potential; inside of the membrane becomes more negative than resting membrane potential

11. Define the terms neurilemma, myelin sheath gap (node of Ranvier), myelinated, and unmyelinated.

- Neurilemma - portion of Schwann cell which includes nucleus, cytoplasm, & exposed part of plasma membrane - Myelin sheath gaps (Nodes of Ranvier) - gaps in myelin sheath that occur between adjacent Schwann cells - Myelinated fibers - axons with a myelin sheath (longer or larger axons) - Unmyelinated fibers - without a sheath (dendrites & smaller axons)

23. Explain how the CNS determines whether a stimulus is strong or weak.

- Strong stimuli - produce more frequent action potentials - Weak stimuli - produce less frequent action potentials

27. List 4 rotator cuff muscles.

- Subscapularis - Supraspinatus - Infraspinatus - Teres minor

16. Define the terms voltage, potential difference, current, resistance, insulator, conductor, and Ohm's law.

- Voltage (V) - measure of potential energy generated by separated charge - Potential difference (potential) - voltage measured between two points (a-b) - Current (I) - flow of electrical charge between two points - Resistance (R) - a substance's hindrance to charge flow - Insulator - substance with high electrical resistance - Conductor - substance with low electrical resistance - Ohm's law - relationship between voltage, current, & resistance

13. Contrast white matter and gray matter in the CNS.

- White matter - regions with dense collections of myelinated fibers; primarily fiber tract - Gray matter - contains mostly nerve cell bodies & unmyelinated fibers

26. Define the term synapse.

- a junction that mediates information transfer from one neuron to the next neuron or from a neuron to an effector cell

9. Contrast anterograde movement and retrograde movement.

- anterograde movement - toward axon terminal - retrograde movement - away from axon terminal (removal or recycling)

1. Differentiate between the central nervous system and peripheral nervous system.

- central nervous system (CNS) - brain & spinal cord - peripheral nervous system (PNS) - part of nervous system outside CNS; primarily paired cranial & spinal nerves

17. Describe the three types of ion channels.

- chemically gated (ligand-gated) channels - voltage-gated channels - mechanically gated channels

11. Define Electromagnetic radiation

- emitted wave packets of energy from short gamma rays to long radio waves

Define Hyperopic Eye and its correction

- eye is too short or cornea is too flat so focal point is behind retina; hyperopia is farsightedness -hard to focus on near objects -convex lens correction (convergent lens)

36. Describe the characteristics of the quadriceps femoris.

- four separate heads form flesh of front & sides of thigh - quadriceps tendon- common insertion tendon of the four heads - sole knee extensor - most powerful muscle in body - muscle tone contributes to strength of knee joint - hamstring muscles are antagonists; flex knee

38. Describe the functions of the intrinsic foot muscles.

- help flex, extend, abduct, & adduct toes - support foot arches - one muscle on dorsal aspect of foot; several muscles on plantar aspect (sole)

28. Define the term fascia.

- layers of connective tissue that cover and separate muscles

7. Describe the structure and function of a dendrite. Define dendritic spine.

- main receptive or input regions of neuron - move incoming signals towards the cell body using short-distance signals called graded potentials (not action potentials) - dendritic spines - points of close contact (synapses) with other neurons

3. Name the two principal cell types in nerve tissue.

- neurons - neuroglia

14. Define the terms Emmetropic eye

- normal eye; light focuses properly

6. Describe the 3 types of neurons in the neural layer of the retina.

- photoreceptors - sensory neurons that convert light energy - bipolar cells - bipolar neurons; carry signals to ganglion cells - ganglion cells - generate AP's

35. Explain the importance of thigh abduction and thigh adduction.

- thigh abduction and adduction are important to balance; those movements shift the body's weight over the limb that is on the ground

10. Describe the structure and function of myelin sheaths.

- whitish, lipoprotein covering around most long or large axons - protects axon - electrically insulates fibers from one another - increases transmission speed of nerve impulses (unmyelinated nerve fibers have a slower impulse conduction rate)

24. Differentiate between absolute refractory period and relative refractory period.

-Absolute refractory period - time from opening of Na+ activation gates until closing of Na+ inactivation gates -Relative refractory period - interval following absolute refractory period

8. Explain how blood is supplied to the retina.

-Central artery & central vein of the retina (radiate out from the optic disc) -blood vessels in choroid

21. Describe the diaphragm and list its 3 openings. Explain how its contraction and relaxation cause inspiration and expiration. Name the nerves that supply the diaphragm

-Diaphragm (dia= across; phragm= partition), -broad, dome-shaped structure -large central tendon -openings: aorta, inferior vena cava, and esophagus - prime mover of inspiration -flattens on contraction - increases thoracic volume vertically when contracted -innervated by phrenic nerves

2. List the 3 layers of the eye (most superficial to deepest or deepest to most superficial).

-Fibrous -Vascular -Retina

6. Define the terms perikaryon (soma), chromatophilic substance (Nissl bodies), nucleus, ganglion, tract, nerve, dendrite, and axon.

-Perikaryon (soma)- consists of a spherical nucleus with a conspicuous nucleolus surrounded by cytoplasm - Chromatophilic substance (Nissl bodies) - most active & best developed rough endoplasmic reticulum in the body - Nucleus(ei)- clusters of cell bodies in the CNS; most common - Ganglion(ia)- clusters of cell bodies along the nerves in the PNS -Tracts- bundles of neuron processes in the CNS - Nerves- bundles of neuron processes in the PNS - Dendrites- short, tapering, diffusely branching processes - Axon- slender process extending from neuron

15. Differentiate between suprahyoid and infrahyoid muscles.

-above (superior to) the hyoid bone -below (inferior to) the hyoid bone

9. Compare and contrast aqueous humor and vitreous humor.

-aqueous humor (clear, plasma-like fluid) which is continually flowing; supplies nutrients & carries away wastes -vitreous humor (clear gel)

7. List the general characteristics of the muscles of facial expression.

-control facial expressions -lie in scalp and face, just deep to the skin -thin and variable in shape and strength -important in nonverbal communication -all inverted by cranial nerves VIII (facial nerve)

Define Myopic Eye and its correction

-eye is too long so focal point is in front of retina; myopia is nearsightedness -hard to focus on far objects -concave lens correction (divergent lens)

Define Refraction

-light passing from one transparent medium to another of different optical density has a change in speed & refracts (bends); faster in less dense medium

Define visible spectrum

-part of spectrum human eyes can detect; 400-700 nm

20. Differentiate between the chemoreceptors for taste and smell.

-taste receptors - excited by food chemicals dissolved in saliva -smell receptors - excited by airborne chemicals dissolved in nasal membrane fluids

Define Concave Lens

-thicker at the edges; light rays diverge (spread apart)

Define Convex Lens

-thickest in center; light rays bend so they converge (come together) at focal point

Define Lens

-transparent object curved on one or both surfaces

25. List the two factors affecting conduction velocity.

1. Axon diameter - the larger the axon's diameter, the faster it conducts impulses 2. Degree of myelination - a myelin sheath increases rate of AP propagation

9. Explain the functions of each of the 11 muscles of the face.

1. Corrugator (corrugo=wrinkle: supercilium=eyebrow)- draws eyebrows together 2. Orbicularis oculi (orb=circular; ocul=eye -closes eye 3. Levator labii superioris (leva=raise; labi=lip; superior=above)- opens lips 4. Zygomaticus (zygomatic= cheekbone)- raises lateral corners of mouth upwards (smiling muscle) 5. Buccinator (bucc-cheek)- compresses cheek 6. Risorius (risor=laughter)- draws corner of lip laterally (synergist of zygomaticus) 7. Orbicularis oris (or=mouth)- closes lips 8. Mentalis (ment=chin)-wrinkles chin 9. Depressor anguli oris (angul=angle, corner; or=mouth)- draws corners of lip downwards and laterally 10. Depressor labii inferioris (depressor= deoresses; infer=below)- draws lower lip inferiorly 11. Platysma (platy= broad, flat)- tenses skin of neck

26. Describe the functions of each of the 9 muscles crossing the shoulder joint.

1. Deltoid (delta = triangular) - prime mover of arm abduction 2. Pectoralis major (pectus = breast, chest; major = larger) - prime mover of arm flexion; adducts arm 3. Latissimus dorsi (latissimus = widest; dorsi = back) - prime mover of arm extension; adducts arm 4. Subscapularis (sub = under; scapular = scapula) 5. Supraspinatus (supra = above, over; spin = spine) 6. Infraspinatus (infra = below) 7. Teres minor (teres = round; minor = lesser) 8. Coracobrachialis (coraco = coracoid; brachi = arm) - synergist; doesn't contribute to shoulder joint reinforcement; flexes and adducts humerus 9. Teres major (teres = round; major = greater) - extends and adducts humerus

20. Contrast the functions of the external intercostals and internal intercostals. Explain how the intercostal muscles aid in breathing. Name the nerves that supply the intercostals.

1. External intercostals (inter= between; cost= rib)- superficial layer of muscles between ribs - with first ribs fixed by scalene muscles, pull ribs toward one another to elevate rib cage -increases thoracic volume to allow inspiration (inhalation) -innervated by intercostal nerves 2. Internal intercostals (internal = toward the inside; deep) - with 12th ribs fixed by quadratus lumborum muscles, draw ribs together to depress rib cage - aiding in forced expiration (exhalation) - innervated by intercostal nerves

22. Describe the direction of muscle fibers in the 4 muscles of the abdominal wall. Explain how this arrangement contributes to abdominal wall strength. Describe the linea alba.

1. External oblique (oblique = running at an angle) - largest, most superficial of the 3 lateral muscles; flexes vertebral column & compresses abdominal wall 2. Internal oblique - most fibers run upward & medially; same action as external oblique 3. Transversus abdominis (transverse = running straight across; abdom =abdomen)- deepest, horizontal fibers; compresses abdominal contents 4. Rectus abdominis (rectus = straight) - medial superficial; "six pack"/"washboard" abs; flexes & rotates lumbar region of vertebral column - Linea alba ("white line")- fused rectus abdominis aponeuroses

14. Describe the functions of each of the 3 muscles promoting tongue movement.

1. Genioglossus (geni= chin; glossus= tongue)- protracts tongue 2. Styloglossus (stylo= pertaining to styloid process)- retracts and elevates tongue 3. Hyoglossus (hyo= pertaining to hyoid bone)- depresses tongue

23. Describe the 2 muscles of the pelvic diaphragm. Describe their functions.

1. Levator ani (ani = anus) - broad, thin tripartite muscle (2 parts visible in diagram); supports pelvic organs 2. Coccygeus (coccy = coccyx) - supports pelvic organs - close inferior outlet of the bony pelvis - support pelvic organs - elevate pelvic floor to help release feces - resist increased intra- abdominal pressure to prevent expulsions of contents of bladder, rectum, and uterus

19. Describe the functions of the 4 intrinsic muscles of the back.

1. Splenius (splenion= bandage)- extends or hyperextends head 2. Erector spinae- prime mover of back extension; consists of three columns on each side of vertebral column -Illiocostalis (ilio= ileum; cost= rib)- lateral -Longissimus (longissimus= longest)- intermediate -Spinalis spin= vertebral column, spine)- medial 3. Semispinalis (semi= half)- composite muscle (capitis, cervicis, thoracis); extends vertebral column and head and rotates them to opposite side 4. Quadratus lumborum (quad= four-sided; lumb= lumbar region) -unilateral contraction- lateral flexion -bilateral contraction- extension of lumbar vertebrae

18. Describe the functions of the 2 anterolateral neck muscles.

1. Sternocleidomastoid (sterno = sternum, cleido = clavicle, mastoid = mastoid process) -bilateral contraction: neck flexion - unilateral contraction: contralateral rotation 2. Scalene muscles (scalene = uneven) - anterior, middle, posterior; elevate first two ribs to aid in inspiration; lateral flexion of neck

17. Describe the muscular actions that occur during swallowing.

1. Suprahyoid muscles pull hyoid bone upward & forward, widening the pharynx (muscular tube from region posterior to nasal cavities to esophagus); larynx (voice box) is also pulled upward which covers it with the epiglottis (elastic cartilage at back of throat which prevents inhalation of food into the lungs) 2. Small muscles elevate the soft palate (soft portion in the roof of the mouth) to close off the nasal passages; prevents food from entering the nasal cavity 3. Pharyngeal constrictor muscles propel food into the esophagus 4. Infrahyoid muscles return hyoid bone and larynx to their more inferior positions as swallowing ends

12. Describe the functions of each of the 4 muscles of mastication.

1. Temporalis (tempora= time)- a prime mover of jaw closure; elevates and retracts mandible 2. Masseter (maseter= chewer)- another prime mover of jaw closure; elevates mandible 3. Lateral pterygoid (lateral= away from median plane; pterygoid= wing like)- forward sliding and side-to-side grinding movements of lower teeth 4. Medial pterygoid (medial= toward median plane)- promotes

5. List the three special characteristics of neurons.

1. extreme longevity - over 100 years with good nutrition 2. amitotic - most neurons don't divide and can't be replaced 3. exceptionally high metabolic rate

25. Explain the functions of each of the 3 muscles of the anterior thorax and 3 muscles of the posterior thorax

Anterior Thorax: 1. Subclavius (sub = under, beneath; clav = clavicle) - helps stabilize & depress pectoral girdle 2. Pectoralis minor (pectus = chest, breast; minor = lesser) - with ribs fixed, protraction & depression of scapula 3. Serratus anterior (serratus = saw)- medially rotates scapula Posterior Thorax: 1. Trapezius (trapezion = irregular four-sided figure) - extension of neck; elevation and retraction of scapula 2. Rhomboids (rhomboid = diamond shaped) - minor and major; stabilize and retract scapula 3. Levator scapulae - elevation of scapula

8. Describe the structure and function of an axon. Define nerve fiber, axon collateral, axon hillock, terminal branch, axon terminal, trigger zone, and secretory region.

Axon - slender process extending from neuron; generates nerve impulses & transmits them typically away from the cell body along the plasma membrane - Nerve fibers - long axons - Axon collaterals - occasional axon branches, if present - Axon hillock - cone-shaped area of neuron where axon arises - Terminal branches - profuse branches at axon's end; 10,000+ - 'Axon terminal (terminal boutons, synaptic bulb, synaptic knob) - knoblike distal endings of the terminal branches - Trigger zone - junction of axon hillock & axon where nerve impulses are generated -Secretory region - the axon terminals; where neurotransmitters are released

Structure and function of: Conjunctiva

Conjunctiva - transparent mucous membrane covering the anterior surface of eye & lining the eyelids; covers only the "whites of eyes", not the cornea -produces a lubricating mucus that prevents eye from drying out -conjunctivitis - inflammation of the conjunctiva

34. Differentiate between channel-linked receptors and G protein-linked receptors.

Direct - neurotransmitters that bind to & open ion channels -promote rapid responses (channel-linked receptors) Indirect - neurotransmitters that act through second messengers -promote long-lasting effects (G protein-linked receptors)

Define Effort

Effort- force applied to a lever

27. Identify types of synapses based on structural connections, information flow, and type of stimulus.

Electrical synapses - specialized to allow the flow of ions between neurons; less common type Chemical synapses - specialized for release & reception of neurotransmitters

8. Describe the epicranius. List its three main parts and describe the function of each.

Epicranius (occipitofrontalis) (epi=over, cran=skull)- bipartite (2 part) muscle with a wide aponeurosis connecting the 2 muscle parts 1. Frontal belly (frontalis)- raises eyebrow 2. Occipital belly (occipitalis) pulls scalp posteriorly 3. Epicranial aponeurosis- connective tissue sheet connecting the frontal belly and occipital belly

33. Differentiate between excitatory and inhibitory neurotransmitters. Differentiate between direct and indirect actions of neurotransmitters.

Excitatory neurotransmitters - cause depolarizations Inhibitory neurotransmitters - cause hyperpolarizations

31. Differentiate between an excitatory synapse and an inhibitory synapse.

Excitatory synapse - neurotransmitter binding causes depolarization of postsynaptic membrane Inhibitory synapse - neurotransmitter binding causes hyperpolarization of postsynaptic membrane

1. Describe the structure and functions of eyebrows

Eyebrows - short, coarse hairs that overlie the supraorbital margins of the skull -shade eye from sunlight -prevent perspiration from reaching eye

3. Describe the fibrous layer of the eye & its structures (sclera, cornea).

Fibrous layer - outermost coat of eye composed of dense connective tissue; two regions 1. Sclera - posterior, glistening white, opaque region 2. Cornea - anterior, clear region; bulges anteriorly

6. State the arrangement of load, fulcrum, and effort in first-class, second-class, and third-class levers (Figure 10.4, page 325). Describe an example of each in the body.

First class lever- load-fulcrum-effort(R-F-E) Exs.-seesaw, scissors lifting head off chest Second class lever-fulcrum-load-effort (F-R-E). Exs.- wheelbarrow, standing on your toes Third class lever-load-effort-fulcrum(R-E-F) Exs- tweezers or forceps, biceps muscle of arm

13. Contrast focusing for distant vision and focusing for close vision.

Focusing for distant vision: -eyes are best adapted for distant vision -ciliary muscles are relaxed & lens is thin (low refractory power) Focusing for close vision: -eyes must make continuous adjustments (3):accomodation of the lens, constriction of the pupils, convergence of the eyeballs

Define Fulcrum

Fulcrum-support or point on which a lever pivots

5. Describe the inner layer (retina) of the eye & its structures (pigmented layer, neural layer).

Inner layer (retina) - delicate membrane forming innermost layer; two layers -pigmented layer of the retina - outer layer; pigment cells absorb light & prevent it from scattering, phagocytize fragments of photoreceptors, and store vitamin A - neural layer of the retina - transparent inner layer that contains 3 types of neurons

31. Describe the actions of the intrinsic muscles of the hand. Explain thumb movements.

Intrinsic hand muscles - small muscles lying entirely in the hand - all found in the palm; no muscles on hand's dorsal side - move metacarpals & fingers - control precise movements (e.g.,threading a needle) - main finger abductors & adductors - produce opposition of thumb Thumb movements - are defined differently because the thumb lies at a right angle to the rest of the hand -Flexion: thumb - bends medially along the palm; fingers - bend anteriorly (towards palm) -Extension:thumb - points laterally("thumbs up"); fingers - move posteriorly (away from palm)

13. Differentiate between intrinsic and extrinsic tongue muscles.

Intrinsic tongue muscles: -made up of muscle fibers that curl, squeeze, and fold during speaking and chewing -change the shape of the tongue and make it nimble -do not really move the tongue Extrinsic tongue muscles: -anchor and move the tongue all are innervated by cranial nerve XII (hypoglossal nerve)

Structure and function of: Lacrimal Apparatus

Lacrimal apparatus - the lacrimal glands & the ducts that drain lacrimal secretions into the nasal cavity -lacrimal glands - located in the orbits above the lateral ends of the eyes; secrete lacrimal secretions lacrimal secretions (tears) - dilute saline solution containing mucus, antibodies, & lysozyme (enzyme that destroys bacteria) clean & protect eye surface moisten & lubricate eyes -excretory ducts - carry tears from lacrimal glands to eyes -tears drain from eyes into the lacrimal sacs then nasolacrimal ducts which empty into the nasal cavity

10. Describe the structure and function of the lens. Explain the effects of aging on the lens.

Lens - biconvex, transparent, flexible, avascular structure that can change shape to precisely focus light on the retina Aging effects: -lens becomes more compact, denser, & less elastic -presbyopia - lens loses flexibility; impairs ability to focus light properly -cataract - clouding of lens

4. Define Lever

Lever- a rigid bar that moves on a fixed point called fulcrum

21. Describe the structures of the olfactory epithelium, olfactory sensory neurons, and olfactory nerves.

Olfactory epithelium - organ of smell; yellow-tinged patch of pseudostratified epithelium located in the roof of the nasal cavity

Structure and function of: Eyelids

Palpebrae (eyelids) - thin, mobile, skin-covered folds -protect eyes anteriorly -eyelashes - project from free margin of each eyelid -palpebral fissure - slit between eyelids -medial & lateral commissures - angles of the eye -lacrimal caruncle - fleshy elevation containing glands that secrete a whitish, oily secretion, fancifully called Sandman's eye-sand -tarsal plate - connective tissue sheet that supports eyelid -tarsal glands - modified sebaceous glands; oily secretion keeps eyelids from sticking together -typical sebaceous glands are also present; associated with eyelash follicles -levator palpebrae superioris - muscle that raises upper eyelid

24. Define the term perineum. Name the 2 sphincters and describe their functions.

Perineum - body region inferior to the pelvic diaphragm; stretches between the two sides of the pubic arch -External urethral sphincter (sphin= squeeze) - urination -External anal sphincter - defecation

Define Resistance (load

Resistance(load)- object moved by effort .

7. Describe the 2 types of photoreceptors.

Rods - respond to dim light -used for peripheral and night vision -more numerous -more sensitive to light Cones - respond to bright light -high-resolution color vision -macula lutea - oval region at posterior pole; contains mostly cones -fovea centralis - minute central pit in macula lutea; contains only cones

16. List differences between rods and cones.

Rods: -sensitive to dim light (night vision, peripheral vision) -contain only 1 type of pigment -perceived input is in gray tones only -as many as 100 rods feed into a ganglion cell -results in fuzzy & indistinct images Cones: -need bright light for activation (low sensitivity) -each cone has 1 of 3 types of pigment -perceived input is vividly colored -each cone in fovea feeds to single ganglion cell -vision is detailed & has high resolution

12. Contrast the processes used by Schwann cells and oligodendrocytes to form myelin sheaths.

Schwann-

21. Order the steps in action potential generation (Figure 11.11, page 402).

Step 1. Resting state: all gated Na+ and K+ channels are closed; leak (ungated) channels are always open Step 2. Depolarization: Na+ channels open Step 3. Repolarization: Na+ channels are inactivating (inactivation gate) & K+ channels open Step 4. Hyperpolarization: some K+ channels remain open & Na+ channels reset

29. Order the steps in information transfer across chemical synapses (Figure 11.17, page 409).

Step 1: Action potential arrives at axon terminal Step 2: Voltage-gated Ca2+ channels open & Ca2+ enters the axon terminal Step 3: Ca2+ entry causes synaptic vesicles to release neurotransmitter by exocytosis Step 4: Neurotransmitter diffuses across the synaptic cleft & binds to specific receptors on the postsynaptic membrane Step 5: Binding of neurotransmitter opens ion channels, creating graded potentials Step 6: Neurotransmitter effects are terminated

16. Describe the functions of each of the 4 suprahyoid muscles and 5 infrahyoid muscles.

Suprahyoid: 1. Digastric (di= 2; gaster= belly)- anterior and posterior bellies united by a central tendon connected to hyoid bone; open mouth and depress mandible 2. Mylohyoid (myle= molar)- elevates hyoid bone and floor of mouth 3. Stylohyoid- elevates and retracts hyoid bone 4. Geniohyoid (geni=chin)- pulls hyoid bone superiorly and anteriorly Infrahyoid: 1. Thyroid (thyro= thyroid cartilage) - superior continuation of sternohyoid muscle; depresses hyoid; elevates larynx if hyoid fixes 2. Sternothyroid (sterno= sternum)- pulls larynx and hyoid bone inferiorly 3. Omohyoid (omo= shoulder)- superior and inferior bellies originate at scapula; depresses and reacts hyoid 4. Sternohyoid- pulls larynx and hyoid bone inferiorly 5. Pharyngeal constrictor muscles- superior, middle, and inferior muscles; constricts pharynx when swallowing

28. Define the terms synaptic cleft and synaptic delay.

Synaptic cleft - fluid-filled space separating presynaptic & postsynaptic membranes Synaptic delay - time needed for neurotransmitter's release, diffusion across synaptic cleft, & binding to receptors

4. Describe the vascular layer of the eye & its structures (choroid, ciliary body, iris, pupil).

Vascular layer (uvea) - pigmented middle layer of eyeball; three regions 1. choroid - blood vessel-rich, dark brown membrane forming posterior 5/6 of the vascular layer 2. ciliary body - thickened ring of tissue that encircles lens 3. iris - visible, colored part of eye lying between cornea & lens 4. pupil - round central opening of iris; regulates amount of light that enters eye

32. Explain the chemical classes of neurotransmitters. Place a specific neurotransmitter in its chemical class (only responsible for neurotransmitters mentioned in lecture).

ch 11 pt 4

10. List the general characteristics of the muscles of mastication.

chewing

11. Name the cranial nerve that innervates the following groups of muscles: muscles of facial expression, muscles of mastication, and extrinsic tongue muscles.

cranial nerve V (trigeminal nerve)

5. Explain mechanical advantage and mechanical disadvantage. Differentiate between a power lever and a speed lever.

mechanical advantage - effort farther than load from fulcrum mechanical disadvantage - effort nearer than load to fulcrum power lever - lever that operates at a mechanical advantage speed lever- allows a load to be moved rapidly over a large distance with a wide range of motion

1. Describe the actions of prime movers (agonists), antagonists, synergists, and fixators.

prime movers (agonists) - muscles that have the major responsibility for producing a specific movement antagonists - muscles that oppose or reverse a particular movement synergists - assist prime movers fixators - synergists that immobilize a bone or muscle's origin

30. Differentiate between a graded potential and an action potential.

slide 12 ch. 11 pt 4